Drone video from 2018: https://www.youtube.com/watch?v=M1T9ZbytyFo
Arecibo Observatory Collapsed
11–20 of 337 posts
Re: Arecibo Observatory Collapsed
#12RIP, buddy. I almost feel like I should be seeing a black banner on HN today.
Re: Arecibo Observatory Collapsed
#13Q: Now, 007, do try to return this equipment in pristine condition.
007: I'll do my best.
Q: That's what I was afraid of.
Re: Arecibo Observatory Collapsed
#14I've heard that radio astronomy was greatly supported by the military because it can be used to monitor for incoming ICBMs. I guess if Arecibo were still used for such purposes, they wouldn't have let it fall into disrepair. How is such monitoring conducted in this day and age?
It went thru the journalist filter a million times until unrecognizable.
The first answer is ICBMs are, now a days, mostly an IR optical thing.
The flightpath of most Russia to US ICBMs would never have passed over the observatory, obviously, but it was a major radar technology research site in the early years.
Re: Arecibo Observatory Collapsed
#15As sad as this is, I'm glad the NSF didn't try to repair it now. There could have been people on the platform when it gave way.
Re: Arecibo Observatory Collapsed
#16"Too big to fail" apparently doesn't apply for science projects.
To put this in perspective, at the cost of a single F-35A, Arecibo could be running for ~7y with funding at 2011 levels.
Re: Arecibo Observatory Collapsed
#17It might seem like they should have more redundancy - one cable broke, then a second, and just a week later the whole thing falls apart - but for structures held in place by tension it doesn't work like that.
A bicycle wheel has redundant spokes: you could design a wheel with 66% of the typical number of spokes and it would work OK. But if you do break a spoke, the wheel will start deforming straight away. If you can't replace the spoke, one piece of advice is to loosen the spoke directly opposite the broken one to even out the distribution of force.
Re: Arecibo Observatory Collapsed
#18So, one thing that isn't clear to me. They were already planning to decommission the structure, so was this a planned collapse, or did this happen literally right after their announcement by coincidence?
If its the latter, I'm very glad they made the call to not try to fix this thing. It would have been so much more tragic had someone been up on the sub-reflector/instrument assembly. Good call by the powers that be to keep it clear.
Re: Arecibo Observatory Collapsed
#19So, one thing that isn't clear to me. They were already planning to decommission the structure, so was this a planned collapse, or did this happen literally right after their announcement by coincidence? If its the latter, I'm very glad they made the call to not try to fix this thing. It would have been so much more tragic had someone been up on the sub-reflector/instrument assembly. Good call by the powers that be t…
My understanding is the fact that this was possible (even likely) was why they decided not to attempt repairs. Basically, the second cable should not have snapped if it was still at design strength, so its failure put the strength of the others (and hence the entire structure) in doubt.
Re: Arecibo Observatory Collapsed
#20It might seem like they should have more redundancy - one cable broke, then a second, and just a week later the whole thing falls apart - but for structures held in place by tension it doesn't work like that. A bicycle wheel has redundant spokes: you could design a wheel with 66% of the typical number of spokes and it would work OK. But if you do break a spoke, the wheel will start deforming straight away. If you can…
This is not a matter of incompetence. They even had auxiliary cables installed some time ago, one of these was the first to fail.
All well-known best practices don't matter if structures cannot be maintained because the governing bodies deny the necessary funding for maintenance/repairs/operation.
In a sense Arecibo was knowingly "given up".